That works, but it’s impractical. This happens on a daily basis.
Edit: referencing an earlier post which implicated SecondBar as a possible cause: I closed SecondBar, closed ST2 and re-opened, and sure enough, Preferences is no longer grayed-out. I was able to re-open SecondBar, and Preferences is still usable.
I suppose at some point it will go away again, but perhaps now I have a work-around.